Oral appliance for administration of electrical stimulation and method for the use thereof

ABSTRACT

An oral appliance for use with a subject in his/her mouth includes a flexible tube having an input end and an output end and an electrode coupled to the flexible tube adjacent the output end. The flexible tube is adapted to be positioned in the subject&#39;s oral cavity with the output end positioned in a posterior region of the oral cavity. The electrode is adapted and configured to administer an electrical stimulation to the posterior region of the oral cavity. An electrode lead is disposed within the flexible tube and connected to the electrode. An electrical stimulation control unit is connected to the electrode lead. A method of administering an electrical stimulation to a posterior region of an oral cavity of a subject is also provided.

This application is a continuation of U.S. application Ser. No.14/013,470, filed Aug. 29, 2013, which is a continuation of U.S.application Ser. No. 12/424,191, filed Apr. 15, 2009, now U.S. Pat. No.8,540,660, which application claims the benefit of U.S. ProvisionalPatent Application No. 61/071,144, entitled Swallowing Air Pulse TherapyMouthpiece and Method for the Use Thereof and filed Apr. 15, 2008, theentire disclosures of which are hereby incorporated herein by reference.

TECHNICAL FIELD

The present invention relates generally to an oral appliance used toadminister a stimulus to a human or animal to elicit and/or facilitate adesired physiological response and in particular, to a mouthpiece fordelivering a substance to a human or animal to elicit and/or facilitateswallowing and a method for the use thereof.

BACKGROUND

Dysphagia is a condition in which a person has difficulty swallowing,characterized by impaired transport of saliva, drink, and food frommouth to stomach. Dysphagia results from disease, or damage, to theneural and/or aerodigestive tract structures that produce swallowing(Logemann, 1998). Often, dysphagia presents in stroke patients, patientswith other acute neurological conditions, patients having Parkinson'sdisease or other neurodegenerative diseases, cerebral palsy or chronicobstructive pulmonary disease (COPD) and/or in response to variouscancer treatments, wherein the patient has difficulty in, and/orexperiences pain with, swallowing. Likewise, other patients may exhibitvarious swallowing, speech, salivary and/or oral sensory impairments.Dysphagia compounds these health problems via resultant complications,most commonly aspiration pneumonia secondary to entry of saliva or foodinto the lungs, dehydration and malnutrition (Smithard et al., 1996). Assuch, some deaths attributed to stroke, may actually be caused bydysphagia and the resulting complication of pneumonia. Thesecomplications may also lead to extended hospital stays, emergency roomvisits, re-admissions, long-term institutional care and need forexpensive respiratory and nutritional support. The cost of dysphagia toNorth American health care systems is estimated to exceed 1 billion USDannually (Agency for Health Care Research and Quality, US Centers forDisease Control and Prevention). Moreover, because dysphagia is mostcommon among the elderly, its prevalence will increase as the populationages over the next 40 years.

In response, various techniques and treatments have been developed toinduce or stimulate swallowing, which can provide various therapeuticbenefits to the patient or user. For example, as disclosed in US Pub.No. 2006/0282010A1, entitled Oral Device (the entirety of which ishereby incorporated herein by reference), a device and method forinducing swallowing in a patient includes delivering one or more gaspulses to a predetermined area of the mouth and/or throat. The deliverydevice includes a molded dental splint that is fitted over the patient'slower teeth and is disposed between the teeth of the user.

Another swallowing therapy is VitalStim, which applies electricalstimulation to the neck overlying the laryngeal muscles with the goal ofaugmenting laryngeal elevation during swallowing (Freed et al. 2001).

SUMMARY

The present invention is defined by the following claims, and nothing inthis section should be considered to be a limitation on those claims.

In a first aspect, one embodiment of an oral appliance for delivering asubstance to the mouth of a user includes a flexible tube having aninlet portion, a first curved portion forming an ear loop connected tothe inlet portion, a second curved portion forming a lip bend connectedto the first curved portion, and an outlet portion extending from thesecond curved portion. In one embodiment, the outlet portion may alsoinclude a third curved portion and an end portion having a gas exitport. In one embodiment, the end portion is also curved. In oneembodiment, the first and second curved portions may have a curvature ina first plane, and the third curved portion may have a curvature in asecond plane non-parallel to the first plane.

In one embodiment, the oral appliance includes a second tube portionalso having an ear loop, lip bend and gas exit port. The inlet portionsof the first and second tube portions can be connected. In oneembodiment, the outlet portions of the first and second tube portionsare connected by a manifold.

In another embodiment, an oral appliance for delivering a substance tothe mouth of a user includes a housing having an inlet portion, a riserportion extending upwardly from the inlet portion and a curved outletportion. The outlet portion has a pair of branches extending laterallyoutwardly from the riser portion. A flexible tube is coupled to thehousing and extends through the inlet portion, the riser portion and outof at least one of the branches of the outlet portion. The flexible tubehas an end portion extending from the outlet portion of the housing. Theend portion has a fluid exit port positioned downstream of the outletportion of the housing. In one embodiment, the curved outlet portion mayhave a first curvature when viewing the curved outlet portion from afirst direction. The curved outlet portion may also have a secondcurvature when viewing the curved outlet portion from a seconddirection, wherein the first and second directions are non-parallel.

In another aspect, a method of delivering a substance to a predeterminedlocation in a user's mouth includes disposing a flexible tube between anouter side of a row of teeth and an inner surface of a cheek. Theflexible tube has an exit port positioned in a rear region of the mouth.No portion of the flexible tube is disposed between the upper and lowerteeth of the user such that the upper and lower teeth can be closedagainst each other or in close approximation to each other. The methodfurther includes dispensing a substance through the exit port. Variousembodiments of the method may also include disposing a curved portion ofthe flexible tube around an ear of the user, and/or disposing a curvedportion around a lip of the user. In various embodiments, the flexibletube may be disposed between lateral surfaces of lower teeth and thecheek of the user, or between lateral surfaces of upper teeth and thecheek of the user. In one embodiment, orientation indicia may beprovided to instruct the user about the proper orientation of the devicerelative to the user and/or substance supply/control unit.

In yet another aspect, a method for assembling a substance deliverydevice includes forming the flexible tube, for example to define an earloop, lip bend and curved end portion. The method of assembling mayinclude fitting a tube within a channel formed in a housing.

The various aspects and embodiments provide significant advantagesrelative to the prior known devices. In particular, the oral appliancecan be made easily and quickly without having to customize the device toa particular user. The flexible tube follows the natural contours of theuser's face and mouth. Moreover, the flexible tube is self-supporting inthe preferred location in the user's mouth, and is maintained in aproper position even with patients/users experiencing numbness orweakness of the lips, tongue or jaw. The device is not fitted over orbetween the user's upper and lower teeth, and does not have to be heldin place by specific jaw positioning. In this way, the flexible tubing,which is disposed between the user's teeth and cheek, does not interferewith normal speech, eating, drinking swallowing, etc., or with the fluidpulse delivery and swallowing therapy.

In addition, the oral appliance and method for the use thereof does notrequire the patient to follow instructions or produce voluntarymovements of the mouth. Rather, the therapy involves the delivery of atrain of at least one pulse of a substance to the patient, who is apassive recipient. This can be important since patients at risk ofdysphagia may be unable to follow complex instructions or producevoluntary movements. In another aspect, however, the therapy can beapplied in association with voluntary attempts to swallow by a patient.In other aspects, the therapy can be used to enhance behavioral therapy,for example, by providing information about the swallow, obtained fromphysiological recordings, to the patient, as a form of (bio)feedback. Inaddition, patients do not need to be able to eat by mouth, meaning theycan receive the therapy when a nasogastric or gastrostomy tube is inplace. In addition, the mouthpiece and method can be used outside of aclinical setting, for example at home, which has advantages over othertypes of therapy such a VitalStim. Moreover, the device is relativelynon-invasive, and does not require any intrusion through the patient'snose and pharynx.

The foregoing paragraphs have been provided by way of generalintroduction, and are not intended to limit the scope of the followingclaims. The various preferred embodiments, together with furtheradvantages, will be best understood by reference to the followingdetailed description taken in conjunction with the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of a first embodiment of an oral appliance.

FIG. 2 is a partial side view of the oral appliance shown in FIG. 1taking along line 2-2.

FIG. 3 is a partial, enlarged view of the oral appliance shown in FIG.1.

FIG. 4 is a front view of a user with the oral appliance of FIG. 1located in an operational position.

FIG. 5 is a side view of a user with the oral appliance of FIG. 1located in an operational position.

FIG. 6 is a perspective view of a second embodiment of an oralappliance.

FIG. 7 is a side view of the oral appliance shown in FIG. 6.

FIG. 8 is a plan view of the oral appliance shown in FIG. 6.

FIG. 9 is a front view of the oral appliance shown in FIG. 6.

FIG. 10 is a plan view of a third embodiment of an oral appliancepositioned in the mouth of the user.

FIG. 11 is a partial plan view of portions of an oral appliance disposedin the mouth of the user.

FIG. 12 is a partial, side cross-sectional view of the oral appliance ofFIG. 6 disposed in the mouth of a user.

FIG. 13 is an enlarged, cross-sectional view of one embodiment of atube.

FIG. 14 is a perspective view of one embodiment of the mouthpiece.

FIG. 15 is a perspective view of the mouthpiece shown positioned in asubject's vestibule and showing multiple ports.

FIG. 16 is a perspective view of the mouthpiece shown positioned at thegingival margin of the upper teeth.

FIG. 17 is a perspective view of the mouthpiece shown positioned at theocclusal plane.

FIG. 18 is a perspective view of the mouthpiece shown positioned at thegingival margin of the lower teeth.

FIG. 19 is an illustration of the swallowing air pulse system includinga signal generator, air pressure regulator, mouth piece and system fordelivering a substance.

FIG. 20 is magnified illustration of an aerosol catheter withaerosolized liquid exiting the tip.

FIG. 21 shows an intracortical microstimulation of the lateral primarymotor cortex showing face primary motor cortex.

FIG. 22 shows functional magnetic resonance imaging of swallowing,tongue elevation, and finger opposition.

FIG. 23 shows a lower dental splint for the delivery of oropharyngealair-pulse application.

FIG. 24 shows recordings of laryngeal and respiratory sensors duringbilateral oropharyngeal air-pulse application.

FIG. 25 shows swallowing frequency in relation to oropharyngealair-pulse application.

FIG. 26 shows swallowing rate in a patient with dysphagia.

FIG. 27 shows functional magnetic resonance imaging of oropharyngealair-pulse application.

FIG. 28 shows functional magnetic resonance imaging of air-pulse inducedassociated swallowing.

FIG. 29 shows a buccal mouthpiece for oropharyngeal air-pulseapplication.

FIG. 30 shows swallowing rate during oropharyngeal air-pulse applicationin elderly individuals.

FIG. 31 shows the SWAPT system with attached mouthpiece fororopharyngeal application.

FIG. 32 shows an embodiment of a vibratory SWAPT mouthpiece.

FIG. 33 shows an embodiment of an electrical stimulation SWAPTmouthpiece.

DETAILED DESCRIPTION OF THE DRAWINGS

The terms “top,” “bottom,” “upwardly” and “downwardly” are intended toindicate directions when viewing the oral appliance from the perspectiveof the user. The term “lateral,” as used in this application, meanssituated on, directed toward or running from side-to-side, for exampleand without limitation from one side of the user's mouth to the other.It should be understood that the term “plurality,” as used in thisapplication, means two or more. The term “longitudinal,” as used in thisapplication means of or relating to length or the lengthwise direction.The term “coupled” as used in this application means connected to orengaged with whether directly or indirectly, for example with anintervening member, and does not require the engagement to be fixed orpermanent, although it may be fixed or permanent, and includes bothmechanical and electrical connection. It should be understood that theterm “substance” as used in this application includes without limitationa fluid, such as a gas, liquid or combination thereof (including anaerosolized liquid), and/or a powder, including particles entrained inany fluid, or combinations thereof. The terms “includes” and “including”as used in this application mean includes and including withoutlimitation.

As disclosed herein, a method and apparatus are provided for deliveringor applying at least one uni-modal or multi-modal sensory stimulus tothe receptive field(s) of at least one sensory cranial nerve within theoral cavity, oropharynx, and pharynx of a human or other animal for thepurpose of (1) initiating, evoking or facilitating swallowing, speechproduction, salivation, or an oral or oropharyngeal sensorimotorbehaviour in a subject, (2) increasing lubrication of the oral cavity,oropharynx, and pharynx in a subject, (3) decreasing oral ororopharyngeal or pharyngeal discomfort in a subject, (4) contraction ofmuscles of the lips, mouth, buccal area, tongue, jaw, soft palate,pharynx, larynx, any of which could result in muscle strengthening withrepeated use of the oral appliance; (5) movement of the lips, mouth,buccal area, tongue, jaw, soft palate, pharynx, larynx, includingelevation of the larynx, including pre-swallow oral transport movementsand pre-swallow chewing-like movements; and/or (6) sensations from theoral cavity or oropharynx that include somatic, thermal or gustatorysensations. For example, the Swallowing Air-Pulse Therapy (SWAPT)embodiments disclosed herein maximize SWAPT-related swallowingfacilitation by delivering multi-modal sensory stimulation to thesubject; by reducing a subject's adaptation to the SWAPT sensorystimulus by altering the parameters of the SWAPT stimulus over time; orby applying SWAPT in association with voluntary preparation to perform abehavior, for example, preparing to swallow, or actual execution of asensorimotor behavior performed by a person/patient such that thefacilitatory effects of SWAPT act as a conditioning stimulus for thesubsequent sensorimotor behavior. These effects are achieved throughvarious embodiments namely: SWAPT with aerosol; various SWAPT mouthpieceembodiments; SWAPT with gustatory stimuli; SWAPT with thermal stimuli;and/or SWAPT with electrical stimulation or kinetic stimulation, and/orcombinations thereof, and methods for delivering (i.e., triggering)SWAPT in association with a sensorimotor behaviour performed by apatient/subject. The application can be performed by direct contact withthe tissues within which sensory receptors are located in the mouth ororopharynx of a human or animal or indirectly by delivering a substancethat comes into direct contact with tissues within which sensoryreceptors are located in the mouth or oropharynx of a human or animal.Examples of direct contact includes without limitation placing the oralappliance in direct contact with an area of the mouth of a human oranimal such that the appliance excites sensory receptors located withinthe contacted oral tissues and structures and by a kinetic effect withinthe oral appliance or a part thereof, for example, vibration or byapplying an electrical current to such an area. Examples of indirectcontact include without limitation delivering a fluid, such as a gas,liquid or aerosolized liquid, or a powder to an area in the mouth ororopharynx of a human or animal that includes sensory receptive fields.

The SWAPT embodiments disclosed herein generalize SWAPT-relatedswallowing facilitation by: providing a means of establishing anassociation between the SWAPT sensory stimulation and a sensorimotorresponse (skill) such that the swallowing reflexogenic properties of theSWAPT stimulus are, over training with SWAPT, assumed by thesensorimotor response alone through a process of conditioning; orproviding a means of using SWAPT during eating, thereby generalizingSWAPT beyond saliva swallowing to prandial swallowing. These effects maybe achieved through various embodiments, including methods fordelivering (i.e., triggering) SWAPT in association with a sensorimotorbehavior performed by a subject, for example, triggering SWAPT inrelation to points within the respiratory cycle, in relation toswallowing preparation, or in relation to an attempt to swallow; andmethods for delivering SWAPT to a subject patient during drinking andeating of liquids and solid foods.

Stimuli applied over the receptive field of the superior laryngeal nerve(SLN) are effective in evoking pharyngeal swallowing (Doty, 1968;Miller, 1999). Activating sensory fibers, of the glossopharyngeal nerve(IX) also evokes pharyngeal swallowing, but at higher thresholds(Sinclair, 1970). Sensory inputs to receptive fields innervated by boththe IX and SLN are believed to be the most effective in evokingpharyngeal swallowing (Miller, 1999). Thus, swallowing therapies thatstimulate receptive fields innervated by both the glossopharyngeal andSLN are expected to have a greater facilitatory effect on swallowingthan therapies that excite only IX sensory fibers, or only SLN sensoryfibers. Consistent with this, in one embodiment, SWAPT delivers airpulses (and/or aerosol) to receptive fields innervated by both the IXand SLN. This is a physiologically-based advantage of SWAPT that is notshared by other technologies that stimulate either the IX receptivefield, or the SLN receptive field, but not both. Thus, a method isprovided for simultaneously, or sequentially, stimulating the receptivefields of both the IX and SLN.

Mechanosensitive sensory fibers of the oral and pharyngeal regionssynapse primarily in the trigeminal sensory nucleus within thebrainstem, with fewer synapsing in the nucleus tractus solitariuus(NTS). The NTS is the anatomic location of the so-called “brainstemswallowing centre”, the bilateral neural network within the brainstemthat programs and orchestrates execution of the pharyngeal swallow(Jean, 2001). Taste-receptive sensory fibers (including water receptors)synapse primarily in the NTS. Although oral, pharyngeal, and laryngealsensory inputs synapse in both the trigeminal sensory nucleus and theNTS, only sensory inputs to the NTS (and its surrounding reticularformation) initiate swallowing. Neurons within the NTS are multimodal,that is, they are excited by multiple sensory modalities (e.g.,mechanical, gustatory, thermal) (Dubner, Sessle, Storey, 1978; Miller,1999). Thus, the facilitatory effect of a sensory input of one modalityis expected to summate with the facilitatory effects of sensory inputsof other modalities in terms of leading to action potentials that giverise to triggering of the brainstem swallowing centre and subsequentpharyngeal swallow. One embodiment of SWAPT provides the advantage ofdelivering multi-modal sensory stimulation to the oropharynx or mouth ofa person. That is, the SWAPT air-pulse trains represent both mechanicaland thermal stimulation. Evidence supporting the thermal property of theSWAPT air-pulse train is found in our study by Theurer et al. (2005) inwhich healthy controls reported that the oropharyngeal air-pulse trainswere perceived as cool. Potential mechanisms for this thermal sensoryeffect are described below.

A moving stimulus applied to a given region of the oropharynx evokes aparticular reflex (e.g., swallow, gag, etc.) depending on the pattern ofmovement (e.g., the type of movement, movement direction, movementvelocity). Sensory stimulation with distilled water to receptive fieldsinnervated by the glossopharyngeal (IX) nerve evokes swallowing in theanesthetized cat (Ootani et al., 1995). Water applied to the pharynx iseffective as a stimulus for pharyngeal swallowing in humans (Nichino,1993). Studies in experimental animals have shown that water applied todifferent regions of the pharyngeal mucosa is a more effective stimulusthan pressure in terms of inducing pharyngeal swallowing (Storey, 1968).Neurons within the nucleus tractus solitariuus (NTS) of the brainstemswallowing neural network are multimodal, that is, they are excited bymultiple sensory modalities (e.g., mechanical, gustatory, thermal).Thus, multi-modal stimuli are expected to facilitate swallowing moreeffectively than uni-modal stimuli.

Pharyngeal swallowing is also evoked in experimental animals byoropharyngeal and/or laryngeal application of: sodium chloride (NaCl),sodium sulphate (Na₂SO₄) sucrose, acetic acid, quinine-hydrochloride,and ethanol (Shingai and Shimada, 1976). A sour bolus (i.e., 50% lemonjuice, 50% barium) has been reported to reduce swallowing latency indysphagic patients following stroke, and reduce aspiration in patientswith other etiologies of neurologically-based dysphagia (Logemann et al.1995).

One embodiment of the Swallowing Air-Pulse Therapy with AerosolizedLiquid (SWAPT-AL) system is shown in FIG. 15. The aerosol delivery isregulated by a general control unit 140 (FIGS. 15 and 31). In onepreferred embodiment, the components of the control unit may include areservoir syringe that acts as a holding chamber for a liquid and a capthat articulates with the proximal end of the syringe. The cap housestubing that provides a portal through which air pressure acts on theliquid. The SWAPT includes a catheter with one or more than one lumens.One lumen carries pressurized liquid. A second lumen carries pressurizedmedical air or a biocompatible gas. The catheter may involve one-or-morelumens ejecting air at its distal tip to aerosolize liquid that issimultaneously ejected from one-or-more lumens at its tip and in closeproximity to the exit of the air-carrying lumens. An air-pressureregulator controls the (1) pressure acting on the liquid and gas(lumens) within the catheter, and (2) the duration of a single airpulse. A signal generator controls the duration of a train ofair-pulses, and the frequency of pulses within the train. A pressurizedtank supplies medical air and an associated air-pressure regulator. Theliquid reservoir may include any sealed vessel or tube with at least oneoutlet that may be pressurized by pneumatic, hydraulic or mechanicalmeans. The reservoir may be pre-filled upon manufacture, or be fittedwith a port or opening to facilitate filling by the caregiver or user.

Using the SWAPT system shown in FIG. 31, studies were conducted todetermine optimal parameters of oropharyngeal air-pulse trains in termsof eliciting saliva swallowing in healthy controls, with examination of(a) air pulse train duration, (b) pulse duration, (c) pulse frequency,and (d) pulse pressure. In one study, the system was driven by aportable nebulizer-type air compressor, while in another study thesystem was driven by compressed medical air from a pressurized tank(i.e., output pressure maintained at 40 psi). These studies showed thatmean saliva swallowing rate increased with increases in air-pulsestimulation frequency between 2 and 12 Hz, with a Valvemate regulatorupper frequency limited to 12 Hz. Frequencies of greater than 12 Hz, forexample frequencies up to at least 80 Hz, may have even greaterfacilitatory effects on swallowing. Air-pulse train amplitude andduration had more variable effects on swallowing across subjects.

In an alternate embodiment the catheter may consist of a single lumenconnected to a liquid reservoir. The lumen may be fitted with a nozzleat the distal tip to produce a spray upon expulsion of the reservoircontents. Or alternatively, the lumen may be of a sufficiently smalldiameter at the distal tip to produce a spray of liquid upon expulsionof the reservoir contents.

In a second alternate embodiment, small quantities of pressurized gasand liquid may be sequentially injected into a single lumen catheter viaseparate tubes or channels expending from the gas source and liquidreservoir to entry points located above the distal tip of the cathetershaft, and preferably near the proximal end. The catheter is sealed atthe proximal end, and open at the distal tip. Upon actuation ortriggering, a small bolus of liquid is first injected into the catheter.The channel to the liquid reservoir is then closed by a valve or similarmeans to prevent backflow of the liquid into the reservoir. Next, asmall bolus of pressurized gas is injected at, or proximal to the pointat which the liquid was injected. The pressurized gas serves to forcethe liquid out the catheter tip. The expansion of the pressurized gasupon expulsion assists in the aerosolization of the liquid. To furtherassist in aerosolization, the lumen can be fitted with a tapered nozzleat the distal tip to produce a spray upon expulsion of the liquid bolus.Or alternatively, the lumen may be of a sufficiently small diameter atthe distal tip to produce a spray of liquid upon expulsion of thereservoir contents. Metering valves positioned on each of the channelsconnecting the gas source and liquid reservoir to the catheter can beused to dispense fixed quantities of compressed gas and liquid into thecatheter upon each actuation. The reservoir valves may be manually,mechanically, pneumatically, hydraulically or electrically actuated atthe desired rate of stimulation.

In a third alternate embodiment, the catheter may consist of more thanone distal tip, thus providing a means of delivering aerosolsimultaneously to multiple sites of the oral cavity, oropharynx, andpharynx. The aerosol may, thus, be delivered to receptive fields of theglossopharyngeal nerve and SLN, as well as the trigeminal nerve, thelatter through a distal port positioned within the oral cavity of aperson.

In yet another embodiment, the reservoir may contain a self-pressurizedaerosol formulation consisting of a liquid and a compressed propellantgas such as those commonly used in spray cans or pharmaceutical metereddose inhalers. The reservoir may incorporate a metering valve todispense a fixed quantity of propellant and liquid into the catheterupon each actuation. The reservoir valve may be manually, mechanically,pneumatically, hydraulically or electrically actuated at the desiredrate of stimulation.

The gas pulse or aerosol pulse train or stimulus is directed to a regionof the oral cavity, oropharynx, and/or pharynx by way of a mouthpiecewithin which the catheter is housed. In one embodiment, the distal tipof the catheter is positioned at the molar end of the mouthpiece. In analternate embodiment, the output port through which the aerosolizedliquid is ejected is positioned at another predetermined site within theoral cavity or oropharynx by virtue of the design of the mouthpiece. Themouthpiece may have a plurality of output ports within the oral cavityand oropharynx. This embodiment allows, for example, air pulses to bedelivered to the oropharynx whilst aerosolized liquid pulses aredelivered to a predetermined site within the oral cavity. Thus, the airpulses are directed toward receptive fields of IX and SLN that are knownto play a role in pharyngeal swallowing initiation, while the gustatory(taste) stimului are directed toward receptive fields of the VII and IXnerves that are also involved in taste sensation.

In one SWAPT embodiment, the stimulus may be medical air. In theSWAPT-AL, the stimulus may be aerosolized liquid. In one embodiment, theaerosolized liquid stimuli are delivered within the following ranges:

-   -   Pulse Frequency: 1 Hz to 80 Hz    -   Single Pulse duration: 20 ms to 100 ms    -   Pulse train duration: 0.1 sec to 20 sec    -   Pulse Pressure: negative (−) 80 mm Hg to positive 240 mmHg        (recorded at the distal (molar) end of the mouth piece).        Sub-atmospheric pressure SWAPT generates suction at the point of        delivery wherein fluid can be suctioned from the oral cavity.

In one embodiment, the aerosolized liquid is room temperature distilledwater, or cold distilled water. In alternate embodiments of theinvention, the aerosolized liquid contains one of the following: NaCl,sucrose, quinine, or lemon juice. Each of these liquids is employed atroom temperature, or cold.

In addition to the advantage of providing multi-modal sensorystimulation, SWAPT with aerosolized liquid provides other benefits. Forexample, Dysphagia can result from a lack of saliva, that is,xerostomia. Xerostomia and associated swallowing impairment occurs in anumber of patient diagnostic groups including persons who have undergoneradiation therapy in the region of the salivary glands for treatment ofcancer of the head or neck, persons with certain systemic conditions(e.g., Sjogren's syndrome), and persons taking medications that reducesalivary flow. In patients with dysphagia following radiation therapy,there is evidence that patients perceive their mouths to be even dryerthan objective measures of saliva indicate (Logemann). Furthermore, theseverity of dysphagia is correlated with the degree of perceived mouthdryness (Logemann). Thus, both dry mouth and the perception of dry mouthare problems for patients who have undergone radiation therapy of thehead and neck. In addition to the association between dry mouth anddysphagia, dry mouth is unpleasant for the patient, reducing quality oflife. By delivering aerosolized liquid to the oral cavity, oropharynx,and pharynx, SWAPT with aerosolized liquid provides a method and devicefor lubricating the oral cavity, oropharynx, and pharynx in patientswith dry mouth. In this way, enhanced lubrication may (1) facilitateswallowing, and (2) moisten the upper airway, thus reducing theunpleasant sensation of dry mouth. Because the volumes of liquid arevery small in the aerosolized form of SWAPT, the patient is not put atrisk of aspiration as would be the case in a dysphagic patientswallowing larger volumes of liquid.

Clinical studies of SWAPT conducted in healthy controls and patientshave provided evidence that modifications to an oral splint mightprovide advantages in terms of efficacy and patient comfort of SWAPT. Inparticular, patient feedback suggests that patients felt that amouthpiece that fits over the lower teeth inhibited their swallowing,that is, the air-pulse evoked an urge to swallow but the mouthpiece thenmade it difficult to swallow. Participants indicated that any materialbetween the upper and lower teeth inhibited swallowing, that is, made itmore difficult to swallow. This was the case even when the material wasvery thin, for example 1 to 2 mm in thickness, which would be close tothe just-noticeable difference for jaw opening of 1 mm.

As used in this application, the term “oral appliance” includes an oraldevice, an oral splint, an oral cannula, an oral applicator, a buccalmouthpiece, a buccal appliance, a buccal cannula and/or a mouthpiece.The oral appliance directs stimuli to regions of the oral cavity,oropharynx, or pharynx, of a subject. In one embodiment, a SWAPTmouthpiece 100 sits within the vestibule 110, between the gingivalsurface of the alveolar bone and the cheek. The mouthpiece extends fromthe molar region 112 on one side of the mouth to the opposite molarregion (see FIGS. 11 and 15). In this embodiment, there is no mouthpiecematerial between the upper and lower teeth 114, 116 (FIGS. 16-18).

In one embodiment, shown in FIG. 16, the mouthpiece 100 sits within theupper vestibule 102. In another embodiment, shown in FIG. 18, themouthpiece 100 sits within the lower vestibule 106. In yet anotherembodiment of the device, shown in FIG. 17, the mouthpiece 100 sitsadjacent to the occlusal plane 104 of the upper and lower teeth 114,116, within the vestibule. In one embodiment, the mouthpiece is between5 mm and 20 mm high, and between 1 mm and 4 mm thick. The length of themouthpiece, from right molar region to left molar region ranges from 3cm to 20 cm. In one embodiment of the mouthpiece, the mouthpiece istrimmable, meaning it may be trimmed in length for optimal placement andfit. In edentulous patients, the mouthpiece fits between the upperalveolar margin and the cheek, or the lower alveolar margin and thecheek.

In one embodiment, the mouthpiece 100 is maintained in position by astabilizing piece that fits around the lateral surface of the rear-mostteeth as shown for example in FIG. 10. In one embodiment, as shown inFIGS. 14-18, the mouthpiece is made of dental resin 120. For example,the dental resin (i.e., STA-Vac sheet resin bleaching tray material#62851, 5″ by 5″, 0.040 soft EVA; Buffulo Dental Canada, Division ofBolton Dental Manufacturing Inc., Cambridge Ontario N3C 1Z1) is vacuumformed over an upper Dentoform (a mock-up of the upper dentition andalveolar structures). One or more lengths of fine-bore polyethylenetubing 122 (inner diameter: 0.045″; outer diameter: 0.062″) are attachedto the molded resin 120 along the margin between the teeth and thegingival margin. In one embodiment, one length of tubing extends on theright side of the dental form, and the other along the left side of thedental form by means of a knotted thread. Alternatively, larger borepolyethylene tubing is attached to the molded resin for the purpose ofcreating a conduit through which the aerosol catheter can be advancedwithin the mouthpiece in order to deliver aerosolized liquid. Amalleable wire may also be attached to the molded resin. The wirepermits contouring, if necessary, of the distal orientation of theoutlet 124 of the catheter and provides a continuity that resistsdamage, such as biting by a person and thus releasing a piece ofmaterial that could be swallowed. A second layer of bleaching traymaterial is vacuum formed over the first layer, thereby enclosing thepolyethylene tubing between the two sheets of dental resin. Thebleaching tray material may be trimmed extensively, resulting in asmall, flexible mouthpiece with tubing that exits posteriorlyimmediately posterior to the posterior-most tooth. Anteriorly, thetubing from the right and left sides exits the mouthpiece at themidline, passes between the subject's lips, and extends approximately 25cm anterior to the lips where it connects securely with larger boretubing at a Luer lock, or with another connector.

In yet another embodiment, the mouthpiece is made of dental impressionmaterial. A narrow sheet of dental wax (approximatelength/height/thickness: 170 mm, 13 mm, 4 mm) is formed around an upperDentoform (a mock-up of the upper dentition and alveolar structures;width at molar region: 54 mm). The wax is then removed from theDentoform, while maintaining its contour. An impression of the wax isthen made with dental impression material (3M ESPE Express FTD VinylPolysiloxane Impression Material Putty, 3M ESPE Dental Products, St.Paul, Minn. 55144-1000), effectively creating an impression tray (i.e.,a trough) that approximates the shape of the wax that surrounded theupper dentition. A second, lighter weight dental impression material(i.e., Affinity Hydroactive Impression Material, Vinyl Polysiloxane,heavy body, regular flow, regular set; Clinician's Choice DentalProducts Inc., 1980 Hyde Park Rd., London N6H 5L9) is then injected intothe impression trough until the level of impression material-occupieshalf the height of the impression trough. One or more lengths offine-bore polyethylene tubing (inner diameter: 0.045 inches; outerdiameter: 0.062 inches) are set within the right and left sides of theimpression tray, respectively. Alternatively, larger bore polyethylenetubing is set within the impression tray for the purpose of creating aconduit through which the aerosol catheter can be advanced within themouthpiece in order to deliver aerosolized liquid. The double tubing canalso be extruded as a single piece, such that they can be separated byforce or by pulling to create the two separate sections to go into themouthpiece. A malleable wire may also be set within the impression tray.The wire permits contouring, if necessary, of the distal orientation ofthe outlet of the catheter and provides a continuity that resistsdamage, such as biting by a person and thus releasing a piece ofmaterial that could be swallowed. The tubing exits the impression troughanteriorly and posteriorly through small-bore openings that are placedin the impression material. Additional impression material is theninjected into the trough, over the tubing, such that the tubing is fullysurrounded by impression material within the right and left sides of theimpression trough. The dental impression material is trimmed, resultingin a small, flexible mouthpiece that fits within the vestibule between apatient's upper teeth and the cheek and houses the polyethylene tubing.The polyethylene tubing exits the dental impression materialposteriorly, on the right and left sides, immediately posterior to theposterior-most tooth, and terminates flush with the impression material.The tubing from the right and left sides exits the mouthpiece anteriorlyin the region of the upper central incisor teeth where it passes betweenthe patient's lips and extends approximately 25 cm anterior to the lipswhere it connects securely with larger bore tubing at a Luer lock, orwith another connector.

In yet another embodiment, the mouthpiece is made ofhigh-temperature-heat-resistant silicone with a nylon core. The siliconeis molded in a method similar to that described above for the dentalimpression material mouthpiece. The heat resistant silicone with nyloncore provides a mouthpiece that can be sterilized and, thus, employedrepeatedly by a patient.

The various mouthpiece embodiments may have a plurality of output ports124, 126 as shown in FIG. 15, which are located within the oral cavityand oropharynx. This embodiment allows, for example, air pulses 128 tobe delivered to the oropharynx whilst aerosolized liquid pulses 130 aredelivered to a predetermined site within the oral cavity. Thus, the airpulses 128 are directed toward receptive fields of IX and SLN that areknown to play a role in pharyngeal swallowing initiation, while thegustatory (taste) stimuli are directed toward receptive fields of theVII and IX nerves that are involved in taste sensation.

In various embodiments, the polyethylene tubing 122 exits the mouth atan angle, as shown in FIGS. 16-18. In one embodiment, the tubing exitsthe mouthpiece along the same-horizontal plane as the mouthpiece. Thisdesign is optimal when the mouthpiece is positioned along the subject'socclusal plane. In an alternate embodiment of the mouthpiece, the tubingexiting the oral form is contoured such that, immediately after exitingthe oral form 120, it follows approximately an 80 degree angle. Thetubing then exits the patient's mouth, running between the upper andlower lips. This angle of the exiting tubing is optimal when themouthpiece is positioned within the vestibule 102 along the buccalsurface of the upper teeth, or the vestibule 106 along the buccalsurface of the lower teeth. The angle of the tubing ensures that themouthpiece stays in position along the buccal surface of the upper orlower teeth, or, in edentulous patients, along the upper or loweralveolar margin. Another advantage of this design is that the mouthpiececan be positioned either along the upper or lower teeth, or upper orlower alveolar margin. That is, a single mouthpiece can be used for boththe upper dental arch, or lower dental arch, positions, by orienting thetubing inferiorly, or superiorly, respectively as shown in FIGS. 16 and18. This has advantages for patients with anatomic abnormalities ofeither the upper or lower teeth/alveolar margin, for example, as aresult of surgery and reconstruction for treatment of oral cancer. Thepatient can position the mouthpiece along the intact dental arch.

In another embodiment, the mouthpiece 100 is coated with an oralantiseptic to provide a means of enhancing oral hygiene in the user.This is advantageous since poor oral hygiene has been shown to be astrong predictor of aspiration pneumonia among institutionalizedpatients. The causal link between poor oral hygiene and aspirationpneumonia appears to be aspiration of contaminated oral secretions. Thisis a particular problem among persons with swallowing impairment inwhich aspiration is a frequent feature of the swallowing pattern.Therefore, it may be advantageous for the SWAPT mouthpiece to be coatedwith an oral antiseptic such that use of the device would enhance oralhygiene, in addition to facilitating swallowing.

The various mouthpiece embodiments provide several advantages. Forexample and without limitation, the patient is able to maintain his/herupper and lower teeth 114, 116 in occlusion. This is preferable sincekinematic studies of swallowing have shown that the upper and lowerteeth are positioned along or near the occlusal plane 104 during thepharyngeal stage of swallowing. Thus, the upper and lower teeth may bein occlusion whilst the device is “in situ” in the subject's mouth,occlusion being the preferred posture of the jaw/teeth duringswallowing. The mouthpiece 100 also has a relatively small impact on theresting position of the subject's mouth, tongue, oropharynx, and face.For example, the tongue in rest position does not make contact with themouthpiece. Because the mouthpiece is thin, the subject is able toachieve closure of the lips. The mouthpiece 100 also does not come incontact with pooled saliva in the sublingual region or along the lingualsurfaces of the teeth. Being positioned within the upper or lowervestibule 102, 104, the subject/patient can ingest and swallow liquid orsolid bolus with the mouthpiece in situ. Thus, the mouthpiece may beinserted into the vestibule with the mouthpiece having a small channelsufficient to allow enough gas or aerosolized liquid to pass tofacilitate swallowing and potentially allow the patient to intake andmasticate food and drink while the mouthpiece is in place.

In one embodiment, the mouthpiece is constructed out of a material(s)(single or multi lumen) that would prevent the patient from fragmenting(biting) the mouthpiece. For example, heat resistant silicone issufficiently strong to prevent a person from fragmenting the mouthpiece.The use of a malleable wire within the mouthpiece also permitscontouring, if necessary, of the distal orientation of the outlet of thecatheter and also provide a continuity that is resistant to being bittenthrough and so releasing a piece of material that could be swallowed.The mouthpiece is constructed in such a way as to also preventswallowing (partially) or gagging on the mouthpiece.

As discussed above, neurons within the NTS are multimodal, that is, theyare excited by multiple sensory modalities (e.g., mechanical, gustatory,thermal). Thus, multi-modal stimuli are expected to facilitateswallowing more effectively than uni-modal stimuli. Furthermore,pharyngeal swallowing is also evoked in experimental animals byoropharyngeal and/or laryngeal application of: sodium chloride (NaCl),sodium sulphate (Na₂SO₄), sucrose, acetic acid, quinine-hydrochloride,and ethanol. A sour bolus (i.e., 50% lemon juice, 50% barium) has beenreported to reduce swallowing latency in dysphagic patients followingstroke, and reduce aspiration in patients with other etiologies ofneurogenic dysphagia.

As described above, one method provided to deliver multi-modal sensorystimuli that include a gustatory component for swallowing facilitationis through the use of aerosolized SWAPT, for example through port 126.In various embodiments, the aerosolized liquid 130 contains one of thefollowing: NaCl, sucrose, quinine, or lemon juice. Each of these liquidsis employed at room temperature, or cold.

Another alternate method for delivering multi-modal stimuli that includea gustatory component is by applying a gustatory stimulus to the SWAPTmouthpiece 100. Thus, what is claimed is a flavour-treated mouthpiece.The gustatory stimulus is provided as a manufactured aspect of themouthpiece in the form of a coating or impregnation of the gustatorystimulus that provides a means for the gustatory stimulus to be releasedin the subject's oral cavity when the material elutes over a period oftime as it comes in contact with, and is moisturized by, the subject'soral saliva and oral secretions. In this way, a gustatory stimulus issupplied by the mouthpiece while the mechanical and thermal stimuluscomponents are supplied in the delivered air-pulse trains oraerosol-pulse trains. Thus, the mouthpiece is impregnated with a flavouringredient that elutes over a period of time when moisturized afterinsertion into the vestibule or mouth.

A cool percept associated with the SWAPT air-pulse trains may reflect atleast three mechanisms: (1) the use of room-temperature air providing astimulus that is cooler that the subject's intra-oral temperature, (2)the expansion of the compressed SWAPT air as it exits the tubing withinthe mouthpiece that may reduce the air temperature, and (3) theevaporation of liquid within the mouth by the air-pulse train, that is,the evaporation of saliva, which may contribute to the perception of acool stimulus within the oral cavity or oropharynx. These thermalproperties of SWAPT are seen as an advantage over other technologiesthat utilize an external cooling control system to cool the gas or otheroral stimulus before it enters the subject's mouth. External coolingsystems for delivery of temperature-controlled stimuli within the mouthmay be problematic because of the distance that must be traversedbetween the site of cooling, and the desired site of stimulation withinthe oral cavity or oropharynx. In contrast, the mechanisms that arebelieved to underlie the thermal property of SWAPT operate within thesubject's oral cavity and oropharynx, precluding the need for anexternal cooling control system. Thus, a thermal stimulus is provided tothe oral cavity and oropharynx wherein the thermal property is providedthrough the inherent properties of the stimulus and the stimulusdelivery system, both being located fully within the oral cavity ororopharynx of a person.

In an alternate embodiment, the temperature of the gas 128 oraerosolized liquid stimulus 130 used in SWAPT, and SWAPT-AI,respectively, is altered by means of a control system that is externalto the oral cavity. The control unit 140 may be positioned and set toapply a sensory stimulus to the oral cavity or oropharynx or pharynx atsome predetermined time. This predetermined time point may be defined inrelation to (1) time, (2) in advance of, or simultaneous with, anattempt to perform a swallow, or another behaviour performed by a person(e.g., patient or clinician), or (3) a physiologic event in a person, asdetermined from the output of a transducer positioned on the person,oral or oropharyngeal sensorimotor behaviour, by a person. The controlsystem includes a signal generator and an air-pressure regulator 101,for example a Valvemate regulator, as shown in FIGS. 19 and 31.

In one group of embodiments, the onset and offset of the sensorystimulus (SWAPT or SWAPT-AL) may be triggered in a number of ways,including physiologic events in the patient, for example,respiratory-related movements associated with various phases of therespiratory cycle, laryngeal movement, or electromyographic activity(for example, recorded from surface electrodes placed over thesuprahyoid musculature (i.e., under the chin) that are recorded fromtransducers positioned on the patient; the output signals are comparedwith a predetermined threshold and, if the signal exceeds thepredetermined threshold, the SWAPT stimulus is delivered. The system mayalso be activated by a patient or clinician, for example, by a buttonpress or an alternate manual means of triggering stimulus delivery; thepatient or clinician could, thus, initiate SWAPT or SWAPT-AL in relationto bringing food/drink toward the mouth, or ingesting food, orswallowing food, or when the patients feels ready to swallow. A cue orinstruction may also be provided to the patient as a conditioningstimulus (e.g., an auditory tone) or an instruction to the patient toinitiate a behavior, for example, to commence swallowing or chewing. Thesystem may also be activated on a temporal basis, for example, bytriggering SWAPT or SWAPT-AL every several minutes when swallowing ofaccumulated saliva is desired by a patient. The system may also beactivated on the basis of combinations of these various mechanisms.Thus, the onset of SWAPT or SWAPT-AL could be triggered as a function oftime to occur every three minutes for the purpose of swallowingaccumulated saliva; the offset of the SWAPT stimulus sequence would betriggered based on the occurrence of a swallow (determined from thelaryngeal force sensor) in relation to SWAPT such that SWAPT air-pulsetrains would continue until a swallow occurred, after which it would beterminated and subsequently, be applied again at 3-minute intervals.

Habituation, defined as the reduction of responsiveness to a stimulusafter prolonged or repeated exposure to the stimulus, is a ubiquitousfeature of neural processing. Habituation can be seen as an adaptiveprocess whereby the nervous system ceases to respond to unimportantstimuli within an environment of multiple completing stimuli.Habituation has been demonstrated in human responses to auditory,visual, and somatic stimuli.

One embodiment of the SWAPT 100 provides a means of delivering asequence of distinct air-pulse trains, or aerosol-pulse trains to theoral cavity, oropharynx, or pharynx of a person, where a train isdefined as a series of at least one pulse. The individual air-pulsetrains may vary in terms of the following pulse parameters: pulseduration, pulse amplitude, pulse frequency, and train duration. Theair-pulse trains (of varying pulse parameters) are presented in randomorder within a predetermined sequence. By altering the stimuluscharacteristics of successive pulse trains, habituation to SWAPT orSWAPT-AL is expected to be reduced because the nature of the stimulus isvariable as a function of time. Thus, the salience of the SWAPT stimuliis expected to be maintained over time to a greater degree than would beexpected with a system in which a given sensory stimulus is repeatedlydelivered to the patient/subject. In this way, the predeterminedsequence of variable pulse trains optimizes the facilitatory effect ofSWAPT.

Previous electrophysiological studies in primates (Martin et al. 1993,1995, 1997; Sessle et al. 2005), and NSERC- and HSF funded brain imagingstudies in humans (Martin et al. 2001, 2004; Toogood et al., 2005,2006), have shown that, in addition to known brainstem areas, swallowingis processed within a large-scale inter-hemispheric network of corticalfoci. Many of these foci were localized to sensory and sensoryassociation cortical regions (see FIGS. 21 and 22), underscoring theimportance of sensory inputs in swallowing regulation. After comparingthe effects on swallowing of several sensory stimuli, it was determinedthat air pulses were superior in terms of swallowing facilitation andclinical feasibility. SWAPT directs predetermined trains of discrete airpulses to the posterior aspect of the mouth and oropharynx, near thetonsil (FIG. 23) where receptive fields, innervated by the superiorlaryngeal nerve (SLN) and the pharyngeal branch of the glossopharyngealnerve (GPNph), are believed to be “reflexogenic” for swallowing (Mu andSanders, 2000; Yoshida et al., 2000).

Air-pulse stimulation applied to the peri-tonsillar region of theoropharynx in healthy controls evokes an irrepressible urge to swallow,followed by a frank swallow as verified by laryngeal and respiratorymovement patterns (Therurer et al., 2005), as shown in FIG. 24.Moreover, air-pulse stimulation produces a significant increase in thefrequency of saliva swallowing (FIGS. 24 and 25), with bilateralstimulation having a greater effect than unilateral. These findings werereplicated and extended in to larger samples of healthy controls (N−16,Fortushnick et al; N=15, Girma et al.), and in a preliminary study of 2patients with dysphagia secondary to stroke demonstrates such results asshown in FIG. 26 (Theurer et al. 2005b).

In parallel with various behavioral studies, high-field functionalmagnetic resonance imaging (fMRI) has been used to study the neuralprocessing of oropharyngeal air-pulse application. For example, SWAPTactivates a distributed brain network including the primarysomatosensory cortex and the thalamus, classical motor areas (primarymotor cortex, supplementary motor area, cingulated motor areas and basalganglia) and polymodal regions (including the insula, inferior parietalcortex and frontal cortex) (Soros et al., 2008), as shown in FIG. 26.These cortical areas overlap regions previously implicated in oral andpharyngeal sensorimotor functions such as tongue movement, mastication,and swallowing. Swallows that are produced at short latency afterair-pulse stimulation activate the same cortical network as habitualswallows, suggesting that air-pulse application might be used to “drive”the cortical swallowing network as shown in FIG. 26.

The SWAPT air pulse trains are delivered to the oropharynx via amouthpiece 130 (see e.g., FIG. 23). One embodiment of the SWAPTmouthpiece 130 employed a custom silicone mouthpiece that fit over thelower dentition (FIG. 23). In another embodiment, the SWAPT mouthpiece100 sits within the buccal cavity, between the teeth and cheek (FIG.29). In this embodiment, there is no mouthpiece material between theupper and lower teeth based on patient feedback indicating thatinter-dental material was perceived as inhibiting swallowing. The newmouthpiece is made of 1 mm thick dental resin (i.e., bleaching tray ormouth-guard material) that is vacuum-formed over a Dentoform (a mock-upof the dentition and alveolar structures). Two lengths of fine-borepolyethylene tubing (inner diameter: 0.045 inches; outer diameter: 0.062inches) are attached to the molded resin along the Dentoform marginbetween the teeth and the gingiva, one on the right side of the dentalform, and the other along the left side of the dental form. A secondlayer of resin is vacuum formed over the first layer, thereby enclosingthe polyethylene tubing between the two sheets of dental resin. SWAPTefficacy with the mouthpiece of FIG. 29 was demonstrated in a sample of18 healthy geriatric participants as shown in FIG. 30 (Theurer et al.,2008).

The buccal mouthpiece 100 has several advantages. The patient is able tomaintain his/her upper and lower teeth 114, 116 in occlusion. This ispreferable since kinematic studies of swallowing have shown that theupper and lower teeth are positioned along the occlusal plane during thepharyngeal stage of swallowing. The mouthpiece appears to have arelatively small impact on the resting position of the subject's mouth,tongue, oropharynx, and face. For example, the tongue in rest positiondoes not make contact with the mouthpiece. Because the mouthpiece isthin, the subject is able to achieve closure of the lips. The mouthpiecedoes not come in contact with pooled saliva in the sublingual region oralong the lingual surfaces of the teeth. Being positioned within theupper or lower buccal region, the mouthpiece potentially allows thepatient to ingest and swallow food and drink while the mouthpiece is inplace.

Referring to FIGS. 1-5, another embodiment of a mouthpiece, referred toas an oral cannula 2, for delivering a gas to the mouth of a user isshown. The oral cannula may include a pair of flexible tubes 4, 6configured to be positioned on opposite sides of the face of a user. Ofcourse, it should be understood that the oral cannula may include only asingle tube disposed on one side of the user's face. The oral cannulamay also be configured with two tubes, but with gas being deliveredthrough only one of the tubes in some desired treatment modalities. Theflexible tubes 4, 6 may be made of thermoformed tubing, which can beformed into a particular shape and configuration, but which has someflexibility and ability to conform to the face and mouth of the user. Inone suitable embodiment, the flexible tube is made of polyurethane,polyethylene, PVC, other suitable and biocompatible materials, and/orcombinations thereof. The tubes may have a ⅛^(th) inch outer diameterand a 1/16th inch inner diameter forming a lumen. Of course, other sizetubes may also be suitable, and the cross-sectional shape may becircular, or configured in other geometrical shapes. The tubes may beclear or transparent, translucent, coloured or opaque, and/or variouscombinations thereof, with the visual characteristics varying along thelength of the tube for example so as to provide one or more windows.Each tube may also be formed with a plurality of lumens, or channels, toallow for additional features such as light, sensors, fluid delivery,etc., including for example and without limitation the delivery of anaerosolized liquid 130 through a port 126, shown for example in FIG. 20.In such embodiments, the lumens may run parallel to each other, andinclude for example and without limitation a first inner lumen and asecond exterior lumen formed around the inner lumen, or alternativelytwo or more lumens running side by side. Of course, the plurality mayinclude more than two lumens.

In one embodiment, shown in FIG. 13, a wire 8 runs along a length of atleast a portion of the flexible tubing 4, 6. The wire provides furthershape memory to the flexible tubing. The wire may be co-extruded withthe tube, or may be connected to the tubing by molding, welding,adhesives and the like, or combinations thereof.

Referring to FIGS. 1-5, the flexible tube 4, 6 may be made of,impregnated with, or coated with a flavored material, including withoutlimitation fruit (e.g., lemon), menthol or mint flavors, which may bepleasing to the user and which may facilitate swallowing. The tube mayalso be made of, impregnated with, or coated with, an antistaticmaterial, or alternatively a conductive material. Antistatic materialshave a surface resistivity of between about 10E10 ohm/sq and about 10E12 ohm/sq. Static dissipative materials have a surface resistivity ofbetween about 10E6 ohm/sq. and about 10E12 ohm/sq. Conductive materialshave a surface resistivity of between about 10E1 ohm/sq and about 10E6ohm/sq. Metals typically have a surface resistivity of between about10E-1 to about 10E-5 ohm/sq. Surface resistivity as set forth herein ismeasured pursuant to ASTM test D257. The tubing may also be made of, orcoated with, an antibacterial material. For example, silver impregnationmay provide antibacterial properties.

Each flexible tube 4, 6 includes an inlet portion 10, which ispreferably elongated and may extend from the neck region to the ear ofthe user. The inlet portion has an inlet end portion 12 connected to anadapter (e.g., Y adapter) 14, with the adapter having a feed tube 16connected to an opposite end thereof. A slideable connector 20,configured in one embodiment as a sleeve, is disposed over and slidablyreceives the inlet portions 10 of the tubes. The connector 20 may bemoved back and forth along a portion of the lengths of the inletportions 10 of the tubes so as to lengthen the end portion 12, andthereby secure the tubes under the chin of the user, or to shorten theend portion 12, and thereby loosen the tubes for comfort or removal.

The feed tube 16 is configured to connect to a gas source 22, forexample and without limitation by way of a quick connect 18 having areleasably component, such as a detent. The term “gas” refers to andincludes air, oxygen, and/or any other type of gaseous substancesuitable for breathing by humans, including for example and withoutlimitation Heliox. The gas may also include various medicamentsentrained therein for further treatment of the user, for example variousmedicaments applied via an aerosol such as antibiotics for pulmonaryinfections or COPD medications. The gas source is configured to emitpulses of gas, with the volume, temperature, pressure, duration and/orfrequency being controlled by a central processor and control system.The gas source can alternatively be configured to emit a continuoussource of gas. The system can also be configured to sense therespiratory cycle of the user, such that gas is delivered only during acertain portion of the cycle, e.g., during exhalation. Various exemplarycontrol systems are shown and disclosed in US Pub. No. 2006/0282010A1,entitled Oral Device, the entire disclosure of which is herebyincorporated herein by reference.

Referring to FIGS. 1-5, the pair of tubes 4, 6 are a mirror image ofeach other, or can be folded one onto the other, along a longitudinalaxis 24. As shown in FIGS. 1 and 2, various portions of the tubes may beformed or positioned within a plane 26, although during use, as shown inFIGS. 4 and 5, the tubes 4, 6 conform to the face 28 of the user and isself supported on the face and in the mouth 30, meaning the user and/orcare giver are not required to hold or position the tubes with theirhands, lips, tongue, teeth and/or other devices.

The tubes 4, 6 each have a curved portion 32 forming an ear loopconnected to the inlet portion 10. In one embodiment, the ear loop 32may be encapsulated, or covered with a padding material 40, such asfoam, which provides greater comfort to the user. Of course, it shouldbe understood that other portions of the tube, such as the portion 42running along the face of the user, may also be covered or secured to aninterfacing material, such as a padding, to improve comfort.

Another curved portion 34 forms a lip bend. The curved portion 34 isconnected to the curved portion 32 with an elongated portion 42 thatruns along the face or cheek of the user as shown in FIGS. 4 and 5. Asshown in FIGS. 1-3, the curved portion 34 has a curvature that is lessthan the curvature of the curved portion 32, meaning in this embodiment,the radius of the curved portion 32 is greater than the radius of thesecond curved portion 34. In one suitable embodiment, the curvature ofthe curved portion 34 has an inner radius of about 0.25 inches. Itshould be understood that the curvatures may be other thansemi-circular, such as quarter circular, and may for example becurvilinear, or polygonal (i.e., formed from a plurality of discretelinear segments). The term “curvature” refers to the tube having a firstportion defining a first vector 44 and a second portion defining asecond vector 46, wherein the vectors are co-planar but not the same(meaning they may have different angles or orientations (e.g., parallelbut directed in opposite directions)). It should be understood that acurved portion may have multiple curvatures, for example having acurvature in one plane and another curvature in another plane. Forexample, the curved portion 34, or lip bend, has a plurality ofcurvatures, including a first curvature in a plane 26 as shown in FIGS.2 and 3, and a second curvature of a portion thereof as the curvedportion 34 transitions to an outlet portion 36 having a curvature in aplane 48 substantially perpendicular to the plane 26. It should beunderstood that the curvatures may be formed in multiple planes notperpendicular or parallel to each other. In the embodiment of FIGS. 1-3,the curved portions 32, 34 open in opposite first and second directions50, 52.

The outlet portion 42 extends from the curved portion 32 and terminatesin an end portion 38 having a gas exit port 54. The outlet portion 42has a curvature defined by first and second vectors 44, 46 formingangles 13 of 30° relative to the plane 26. In one embodiment, the length(L1) of the outlet portion is about 1.6 inches (±2.5 mm, e.g., 1.575inches), or 1.760 inches (±0.25 mm) from the inner surface of the curvedportion 32 to the terminal end of the end portion 38, with the endportion extending below the first plane. The end portion 38 may also beformed as a curved portion, having a curvature in the first plane 26that may be 0.75 inches and form a vector 56 at an angle α of about 20°with the vertical plane 48 in which the curved portion 36 of the outletportion lies.

The outlet portion 36, as shown in FIG. 11, is curved such that itextends into the user's mouth 30 and is disposed between the side of arow of upper teeth 58 of the user and the interior surface 60 of theuser's cheek. Of course, it should be understood that the configurationand shape can be altered to accommodate placement along the side of thelower teeth or along the occlusal plane. The end portion 38, or curvedportion, may be directed laterally inwardly at a targeted region of therear of the user's mouth 30 and throat. The end portion is configuredwith the gas exit port 54. In this way, no portion of the tube isdisposed between the user's upper and lower teeth. As such, the tubedoes not interfere with normal speech, eating, drinking swallowing,etc., and does not have to be held in place over or between the user'steeth. In one embodiment, each of the inlet portions, ear loop, lip bendand outlet portion may be integrally formed from a single piece oftubing.

Referring to FIG. 10, an alternative embodiment of an oral cannulaincludes a manifold 62 that extends across the back of the user's mouthbehind the rearmost teeth of the user and connects the tubes 4, 6 onopposite sides of the mouth. The manifold includes one or more gas exitports 64 formed therein, for example thought a side wall of themanifold, rather through an end portion or lumen. In one embodiment, themanifold may be integrally formed with the other portions of the tubes,such that a single loop of tubing forms and defines the cannula.

Referring to FIGS. 6-9 and 12, another embodiment of an oral cannula fordelivering a gas to the mouth of a user includes a housing 70 comprisingan inlet portion 72, a riser portion 74 extending upwardly from theinlet portion and a curved outlet portion 76. The housing may be amolded component, formed for example and without limitation, from aflexible material such as silicone or an elastomeric material. Theinlet, riser and outlet portions are shaped and configured to conformto, and match the contours of, the user's mouth and lips. The housing isfurther configured to hold and shape one or more flexible tubes 78, 80,such that the tubing is properly positioned in the user's mouth withoutinterfering with the various oral functions of the user. As such, thehousing directs the tubing to the sides of the user's mouth between theouter sides of the user's upper teeth 58 and the interior surface of thecheek 60.

The housing 70 may be made of a single piece, for example with one ortwo channels that receive the tubing. For example and withoutlimitation, the tubing may be snap-fitted into the channels. In otherembodiments, the tubing is threaded through openings formed in the tube.In yet other embodiments, the housing includes first and second housingcomponents. One or more tubes, depending on the application, aredisposed between the two housing components, with the housing componentsbeing secured to each other, for example and without limitation, by snapfit, welding, mechanical fasteners, adhesives, bonding, or variouscombinations thereof. The housing may be molded, for example injectionmolded.

As shown in FIGS. 6-9, the inlet portion 72 may have a pair of channels,with the tubes entering the channels in a first plane, for example andwithout limitation a horizontal plane 82. The riser portion 74 extendsupwardly and rearwardly from the inlet portion. The outlet portion 76has a pair of branches 84 that extend laterally outwardly and rearwardlyfrom the riser portion. The outlet portion is curved, and has a firstcurvature when viewing the curved outlet portion from a first direction86 and a second curvature when viewing the curved outlet portion from asecond direction 88, wherein the first and second directions arenon-parallel. In one embodiment, the first and second directions aresubstantially perpendicular. The first curvature 90 matches thecurvature of the front teeth of the user and directs the tubes laterallyand rearwardly along the teeth. The second curvature 92 forms a dip thatprovides clearance for the upper labial frenum.

The flexible tubes 78, 80 are coupled to the housing 70 and extendthrough the inlet portion 72, the riser portion 74 and out of respectiveones of the branches 84 of the outlet portion. Each flexible tube has anoutlet portion with an end portion extending from the outlet portion 76of the housing. In one embodiment, the end portion 94 has a curvaturethat substantially follows and matches the sides of the row of teeth ofthe user. The end portion has a gas exit port 9 positioned downstream ofthe outlet portion of said housing. It should be understood that in oneembodiment, only a single tube is secured through the housing. Inanother embodiment, the end portions may be joined by a manifold 62 asshown in FIG. 10.

In any of the embodiments, the oral cannula is configured withorientation indicia 96, which provides information to the user and/orcare giver about the orientation and positioning of the cannula. Forexample and without limitation, in the embodiment of FIGS. 1-5, indiciacan be positioned on the adapter 14 and/or slide connector 20 toindicate which surface thereof is the front or back. Likewise, in theembodiment of FIGS. 6-9, indicia can be positioned on the housing 70.

Alternatively, in the embodiment of FIGS. 6-9, the shape of the housing70 provides a visual indicator, or indicia, about the orientation of thedevice. In the various embodiments, for example and without limitation,an “R” or “B” can be provided on the back of the connector 20 or othercomponent to indicate “Rear” or “Back,” an “F” can be provided toindicate “Front,” and/or an “L” or “R” can be provided on the sides,front or back to indicate “Left” and “Right” respectively. Tactileindicia, in the form of Braille characters or raisedletters/embossments, can be provided for users and/or care givers withpoor sight or for use in poor lighting conditions. Other suitableindicia include without limitation various text (e.g., “Left” and/or“Right”), arrows, various directional indicia and/or combinationsthereof. With the use of such indicia, the user and/or care giver canproperly locate the oral cannula on the face, and in the mouth, of theuser. The adaptor 14 may also be shaped, for example with an angledportion receiving the feed tube 16, so as to direct the feed tube awayfrom the user and provide indicia to the user about the orientation,similar to the shape of the housing 70. Alternatively, a tab, tape orother marker may be provided on the right and left tubes to identifythem as such.

In operation, the user or care giver disposes the flexible tube, and inparticular the outlet portion 36, between an outer side surface of a rowof teeth 58 (upper or lower) and an inner surface 60 of a cheek. In oneembodiment, tubes are disposed on opposite sides of the mouth. The tubesare positioned such that the exit ports 54 are positioned in a rearregion of the mouth and wherein no portion of the flexible tube isdisposed between the upper and lower teeth of the user such that theupper and lower teeth can be closed against each other. In theembodiment of the FIGS. 1-5, the ear loops 32 are disposed around theears 100 of the user, with the mouth/lip bend being positionedaround/over the lip 102 and the outlet portion of the tube beingpositioned along the side of the teeth as just described. The positionof the connector 20 can then be adjusted to further secure the cannulato the user.

In the embodiment of FIGS. 6-9, the housing 70 is inserted between theupper lip 104 and the front 106 of the upper row of teeth, with thetube(s) being positioned along the side of the teeth as describedherein. As shown in FIG. 10, either embodiment can be further configuredwith the manifold 62 extending across the back of the mouth.Alternatively, in either embodiment of FIGS. 1-9, the outlet portion 36,or end portion 38 thereof, may be cut or trimmed such that the exit port54 is positioned in the proper location in the mouth of the user.

In any of the embodiments, the feed tube 16 is connected to the gassource 22. A gas is then dispensed through the exit port(s) 54, 64,preferably in pulses of predetermine pressure, volume, duration and/orfrequency, with the user then swallowing in response to the pulses ofgas.

Any of the embodiments of the oral cannula can be made easily, cheaplyand quickly without having to make expensive, customized teeth molds.Moreover, the device can be quickly and easily adjusted for a particularuser simply by trimming a portion of tubing if necessary. The flexibletube follows the natural contours of the user's face and mouth, yet hassufficient shape memory to ensure proper placement relative to theuser's face, lips, mouth and teeth. The flexible tube is self-supportingin the preferred location in the user's mouth, and is maintained in aproper position even with patients/users experiencing numbness orweakness of the lips, tongue or jaw. The device is not fitted over orbetween the user's upper and lower teeth, and does not have to be heldin place by specific jaw positioning. In this way, the flexible tubing,which is disposed between the user's teeth and cheek, does not interferewith normal speech, eating, drinking swallowing, etc., or with the gaspulse delivery and swallowing therapy.

Referring to FIG. 32, in one embodiment, the oral appliance, or partthereof, is made of compliant tubing 141 that absorbs forces applied toits inner surface by the internal pressure of the substance beingdelivered through the tubing. For example, pressurized gas, deliveredthrough the oral appliance and originating at its input end, will act onthe compliant tubing with resulting expansion and contraction of thetubing in direct relation to changes in pressure of the substance withinthe tubing. In one instance, a gas, controlled by a pressure regulatorattached to the input end of the oral appliance, and delivered throughthe oral appliance, is applied in discrete pressure pulses, such thatthe region(s) of compliant tubing along the length of the oral applianceexpand and contract, for example, within the buccal cavity. Dependingupon the frequency of pressure variations of the substance within theoral appliance, and associated expansion and compression of thecompliant tubing, a kinetic or vibratory stimulus acts directly upon thesurrounding oral tissues, exciting sensory receptors located in the oralmucosal lining.

In another embodiment, the substance that is delivered through the oralappliance for the purpose of eliciting a physiological response by thehuman or animal user may excite sensory receptors of the oral ororopharyngeal regions through a kinetic or a pressure effect. Thesubstance being delivered via the oral appliance can be applied indiscrete pulses, for example, air pulses. The air-pulse trains sodelivered produce a kinetic effect within the ambient surround of theoral appliance output end, and associated pressures acting upon the oraltissues, exciting sensory receptors. This stimulus may be perceived bythe user as vibratory at some stimulus frequencies.

In one embodiment shown in FIG. 33, the oral appliance provides a meansof positioning a stimulating electrode in the posterior region of themouth of the human or animal user such that electrical stimulation canbe applied to that region. In one embodiment, a bipolar surface skinstimulating electrode 142 is positioned immediately distal to the outputend 124 of the oral appliance, and the electrode leads run within theoral appliance tubing within the buccal region of the user 120, continuewithin the tubing that exits the mouth between the user's lips 122 andexits the tubing to connect to an electrical stimulation control unit143. With the oral appliance in situ within the buccal region, thestimulating electrode contacts the soft tissues of the rear aspect ofthe mouth, providing a method for applying electrical stimulation to theoral cavity with the aim of evoking a physiological response in theuser, such as a swallowing and/or salivation.

Although the present invention has been described with reference topreferred embodiments, those skilled in the art will recognize thatchanges may be made in form and detail without departing from the spiritand scope of the invention. As such, it is intended that the foregoingdetailed description be regarded as illustrative rather than limitingand that it is the appended claims, including all equivalents thereof,which are intended to define the scope of the invention.

What is claimed is:
 1. An oral appliance for use with a subject inhis/her mouth comprising: a flexible tube having an input end and anoutput end, wherein the flexible tube is adapted to be positioned in thesubject's oral cavity with the output end positioned in a posteriorregion of the oral cavity; an electrode coupled to the flexible tubeadjacent the output end, wherein the electrode is adapted and configuredto administer an electrical stimulation to the posterior region of theoral cavity; an electrode lead disposed within the flexible tube andconnected to the electrode; and an electrical stimulation control unitconnected to the electrode lead.
 2. The oral appliance of claim 1wherein the electrode lead extends to the input end of the flexibletube.
 3. The oral appliance of claim 1 wherein the electrode comprises abipolar surface skin stimulating electrode.
 4. The oral appliance ofclaim 1 wherein the output end comprises an opening in the flexibletube.
 5. The oral appliance of claim 1 wherein the wherein the flexibletube is adapted to be positioned in the subject's oral cavity with theoutput end positioned in a pharyngeal region of the oral cavity.
 6. Theoral appliance of claim 1 wherein the flexible tube is adapted to bepositioned in the subject's oral cavity such that occlusal surfaces ofthe subject's teeth are substantially not covered by the flexible tube.7. A method of administering an electrical stimulation to a posteriorregion of an oral cavity of a subject comprising: disposing an outputend of a flexible tube in the posterior region of the oral cavity of thesubject, wherein the input end of the flexible tube is disposedexteriorly of the oral cavity; supplying an electrical current with anelectrical stimulation control unit to an electrode lead disposed withinthe flexible tube; and applying an electrical stimulation to theposterior region of the oral cavity with an electrode connected to theelectrode lead, wherein the electrode is coupled to the flexible tubeadjacent the output end.
 8. The method of claim 7 wherein the electrodelead extends to the input end of the flexible tube.
 9. The method ofclaim 7 wherein the electrode comprises a bipolar surface skinstimulating electrode.
 10. The method of claim 7 wherein the output endcomprises an opening in the flexible tube.
 11. The method of claim 7wherein disposing the output end of the flexible tube in the posteriorregion of the oral cavity comprises positioning disposing the output endin a pharyngeal region of the oral cavity.
 12. The method of claim 7wherein the flexible tube is adapted to be positioned in the subject'soral cavity such that occlusal surfaces of the subject's teeth aresubstantially not covered by the flexible tube.